The Fix's Callum Borchers and Aaron Blake explain President Obama's tough choices about how to react to Russian interference in the 2016 election. (Peter Stevenson/The Washington Post)

The Washington Post is reporting Friday morning that President Barack Obama knew in August that Russian President Vladimir Putin was waging an extraordinary cyberwar on the U.S. presidential campaign, both to discredit the election and try to help Donald Trump win. The Obama administration did not publicly acknowledge all of this until after the election, in December.

In the last few months of the election campaign, behind the scenes — and sometimes publicly — Democrats in Congress were extremely critical of the president for not telling the public about what was happening.

Top members of the Obama administration have since defended that decision as the best of bad choices. Former homeland security secretary Jeh Johnson told Congress earlier this week: "We were concerned that, by making the statement, we might in and of itself be challenging the integrity of the — of the election process itself."

So what really happened? Here is a timeline of how the Obama administration responded to the Russian meddling — and how he was criticized for it.

1960: Russians have been trying to influence outcomes and perceptions of U.S. elections since around this time, say intelligence experts today.

July 2016: Nearly 20,000 election-year emails from Democratic National Committee staff members are published by WikiLeaks, on the eve the 2016 Democratic National Convention. Rep. Debbie Wasserman Schultz (D-Fla.) resigns as chairwoman over some of the emails. Some intelligence Democrats point the finger at Russia.

Middle of summer 2016: Top Democrats in Congress say they realized the extent of the hacking, and that it was from Russia. "In the late summer of last year, it became apparent that the Russians were doing more than gathering foreign intelligence — that they were in fact dumping it in a way designed to potentially influence outcomes, not by affecting the vote machines, necessarily, but by affecting American public opinion with the dumping of these emails," recalled Rep. Adam Schiff (D-Calif.), the top Democrat on the House Intelligence Committee, in a recent committee hearing.

Late July: The U.S. government makes a concerted effort to investigate Russia meddling in the election. As former CIA director John Brennan recalled to Congress in June 2017: "When it became clear to me last summer that Russia was engaged in a very aggressive and wide-ranging effort to interfere in one of the key pillars of our democracy, we pulled together experts from CIA, NSA and FBI in late July to focus on the issue, drawing in multiple perspectives and subject matter experts with broad expertise to assess Russian attempts to interfere in the U.S. presidential election."

July 27: Trump calls on Russia to hack Clinton's emails to see if she didn't turn any over to the FBI that she should have.

Republican presidential nominee Donald Trump says it's "far-fetched" and "ridiculous" to say Russia hacked Democratic Party emails to help him become president. (Reuters)

July 27: Schiff and Sen. Dianne Feinstein (D-Calif.), who are among the eight members of Congress who get regular classified briefings by intelligence officials, write to President Obama "urging that the administration declassify and release any intelligence community assessments related to the DNC hack, and develop a swift and powerful response."

Early August: The Washington Post reports that Obama received an "eyes only" envelope by courier from the CIA that "detailed Russian President Vladi­mir Putin’s direct involvement in a cyber campaign to disrupt and discredit the U.S. presidential race" and to help Trump win. "An intelligence bombshell," The Post called it.

August 2016: The Obama administration discovers some entity trying to break into voter registration systems across states.

Also August: Then-CIA director John Brennan calls his counterpart in Russia and tells them to knock it off.

Aug. 15: The Department of Homeland Security issues a statement warning state governments that some kind of entity was trying to hack into states' voter registration systems. Then-DHS Secretary Jeh Johnson would go on to issue several other statements over the next few months. "In the late summer, fall, I was very concerned about what I was seeing, and this was on my front burner all throughout the pre-election period in August, September, October and early November — to encourage the states to come in and seek our assistance," he told Congress in June 2017. "And I'm glad that most of them, red and blue, did."

(The Washington Post)

September 2016: Obama directly confronted Putin at a world leaders meeting in China, telling him to stop -- or else, according to Post reporting.

September: Top members of Congress get a secret briefing by the intelligence community that Russia is interfering in the election, but to what end, they aren't sure. The intelligence community privately says agencies are conducting a broad investigation. The Washington Post later reported that Senate Majority Leader Mitch McConnell (R-Ky.) voiced doubts about the accuracy of this in those secret meetings.

Sept. 22: Frustrated that the Obama administration still had not made a public statement about the extent of Russian hacking, Schiff and Feinstein, the top Democrats on Congress's intelligence committees, take matters into their own hands and issue a rare public statement attributing the hack to Russia and senior levels of the Russian government. Here it is in full:

Based on briefings we have received, we have concluded that the Russian intelligence agencies are making a serious and concerted effort to influence the U.S. election. At the least, this effort is intended to sow doubt about the security of our election and may well be intended to influence the outcomes of the election—we can see no other rationale for the behavior of the Russians. We believe that orders for the Russian intelligence agencies to conduct such actions could come only from very senior levels of the Russian government. We call on President Putin to immediately order a halt to this activity. Americans will not stand for any foreign government trying to influence our election. We hope all Americans will stand together and reject the Russian effort.

Sept. 28: McConnell and the other top three congressional leaders write a letter urging states to use the federal government's help to prevent hacking into their voter registration systems. It makes no mention of Russia.

Oct. 7: The Russian government hacked into Democrats' emails, according to a public statement by then-Director of National Intelligence James Clapper and Homeland Security Secretary Johnson. They conclude "that the intelligence community is confident the Russian Government directed the recent compromises of e-mails from U.S. persons and institutions, including from U.S. political organizations." This marks the first public U.S. acknowledgment that the Russian government interfered in the election.

November-December 2016: Seven Democratic senators send a short letter to Obama to ask him to declassify details of Russian meddling. "We believe there is additional information concerning the Russian Government and the U.S. election that should be declassified and released to the public," they say.

Dec. 6: Top Democrats send another letter to President Obama asking him to brief "all members of Congress on Russian interference in the U.S. election."

Dec. 9:The Washington Post reports on a secret CIA assessment that concludes Russians intervened in the U.S. election to try to help Trump win the presidency, rather than with the sole goal of undermining Americans' confidence in their electoral systems.

Obama orders a comprehensive review of what happened, going back to 2008, with plans to make it public, The Post reports.

Dec. 29: Obama announces sanctions on Russia for election meddling, kicking out 35 Russians expected to play a role in the hacking and taking over two Russia compounds in the U.S.

December-January: President-elect Trump repeatedly refuses to acknowledge the intelligence community's public assessments — and private briefings to him — that Russia hacked in the election to help him win. "It could have been China," he said as recently as May 2017.

Jan. 6: In what The Washington Post calls a "remarkably blunt assessment," the intelligence agencies release a declassified report saying that Putin ordered the hacking and elevation of fake news in the United States to help Trump win. It determines: Russia “developed a clear preference for President-elect Trump” and repeatedly sought to artificially boost his election chances.

May and June 2017: Former Obama intelligence officials go before Congress to assert that Russia interfered in the election. Former CIA director Brennan testifies before Congress and says this: "It should be clear to everyone that Russia brazenly interfered in our 2016 presidential election process and that they undertook these activities, despite our strong protests and explicit warning that they not do so."

Former CIA director John Brennan testified May 23 before the House Permanent Select Committee on Intelligence about Russia's influence on the 2016 presidential election. (The Washington Post)

June 2017: Former Obama intelligence officials defend waiting until October to announce what they had known for several months, that Russia was interfering in the election. Here's Johnson speaking to Schiff this week:

This was a big decision, and there were a lot of considerations that went into it. This was an unprecedented step. First, as you know well, we have to carefully consider whether declassifying the information compromises sources and methods. there was an ongoing election, and many would criticize us for perhaps taking sides in the election. So that had to be carefully considered. One of the candidates, as you'll recall, was predicting that the election was going to be rigged in some way. And so we were concerned that, by making the statement, we might in and of itself be challenging the integrity of the — of the election process itself.

This was — this was a very difficult decision. But in my personal view, it's something we had to do. It got careful consideration, a lot of discussion. My view is that we needed to do it, and we needed to do it well before the election, to inform the American voters of what we knew and what we saw, and that it would be unforgivable if we did not, pre-election. And I'm glad we did it.